Technical Field
The invention relates to an apparatus and method for separating an end-piece (frequently called an end nozzle), typically an upper end-piece, of a nuclear fuel assembly, the end-piece having an adapter plate formed with passages for receiving thin-walled guide tubes fixed to the adapter plate and to another end-piece of the fuel assembly to form a skeleton.
Present fuel assemblies for pressurized water nuclear reactors comprise such a skeleton, completed by grids for holding fuel rods parallel to each other and to the nodal points of a regular, typically square, lattice. The rods contain nuclear fuel pellets. In most assemblies, the rods do not extend throughout the whole length of the space defined by the end-pieces; in typical fuel assemblies they only project slightly above the uppermost grid.
The fuel assemblies, depleted after one or more cycles -n the reactor, are removed from the reactor vessel and positioned in storage racks placed at the bottom of a de-activation swimming pool. To reduce the volume required for long duration storage of the fuel rods, it has already been proposed to dismantle the assemblies, to remove the rods therefrom and to consolidate the rods into bundles of tightly jointing rods. Dismantling an assembly involves removing an end-piece, consequently cutting the guide tubes and possibly the central instrumentation tube which connects the two end-pieces.